Kane Williamson admits he was fortunate to survive the ultimate "uh oh" moment before mounting a compelling defence of his selection in the New Zealand Twenty20 cricket team.

Without a score past 30 in his previous nine T20I innings, criticised by former Black Cap Simon Doull and nursing a back niggle, captain Williamson had his heart in his mouth before getting off the mark in Tuesday's win over England in Wellington.

A suicidal call for a single was fielded by bowler Mark Wood who had a clear sight on all three stumps and ample time run Williamson out at the non-stirker's end.

Somehow he didn't, handing the skipper a chance to open the shoulders with 72 off 46 balls.

The return to form steered the hosts to 196-5 and a 12-run win to put the Black Caps ahead of winless England in the tri-series.

They'll secure a place in the final against Australia at Eden Park next week if they win the trans-Tasman clash at the same venue on Friday.

Williamson's post-match focus had switched to key games to come but he allowed himself to briefly reflect on his bullet-dodging moment.

"I thought the ball was going to roll a bit further. It didn't and I thought 'uh oh'," he said.

"Sometimes you get a bit of luck; sometimes you get a bit of bad luck. You just think about the next ball and try to stick to your plan."

Williamson hopes a return to form - he had scored a total of 17 runs in his team's three preceding losses - and opener Martin Guptill (65 off 40) will provide a boost heading into the return fixture against Australia.

The Australians coasted to a seven-wicket win in the tournament-opener in Sydney.

Batsman Tom Bruce and wicketkeeper Tom Blundell were both dropped from the squad after that match and replaced by Mark Chapman and Tim Seifert respectively.

The two newcomers shone with late batting cameos, hitting two sixes each, which Williamson said proved vital.

Chapman's 20 and Seifert's unbeaten 14 meant New Zealand finished well above the total of about 180 that had appeared likely.

"They came in with limited opportunities and the way they approached their innings and performed, they were outstanding. It was brilliant to see."